Method and mold for manufacturing an interlocking concrete block

Abstract

A mold and method for manufacturing interlocking concrete blocks. The mold comprises a mold box, comprising two side walls joined to end walls to define a mold cavity, a top face, and a substantially open bottom face. Top insert members are configured to define a space between adjacent blocks, for forming a portion of the transverse profile of the top surface of one block or a portion of the transverse profile of the bottom surface of an adjacent block, or both. A removable draw plate for closing the bottom of the mold box comprises a generally planar floor and bottom insert members configured to define a space between adjacent blocks, for forming a remaining portion of the transverse profile of the top surface of one block or a remaining portion of the transverse profile of the bottom surface of an adjacent block, or both.

The invention claimed is: 
     
       1. A mold for manufacturing at least one interlocking concrete block, the at least one block having a top surface having a transverse profile comprising at least one interlocking structure projecting from or recessed into the top surface, and a bottom surface having a transverse profile comprising at least one complementary interlocking structure projecting from or recessed into the bottom surface, the mold comprising:
 a mold box, comprising:
 two side walls joined to end walls to define a mold cavity, a top face, and a substantially open bottom face; and 
 top insert members configured to define a space between adjacent blocks or a space between a block and a side of the mold box, extending between the end walls of the box substantially from the top face into the mold cavity, for forming a portion of the transverse profile of the top surface of one block or a portion of the transverse profile of the bottom surface of an adjacent block or both; 
 
 and 
 a removable draw plate for closing the bottom of the mold box, comprising:
 a generally planar floor; and 
 bottom insert members configured to define a space between adjacent blocks, or a space between a block and a side of the mold box, extending between the end walls and projecting from the floor into the mold cavity, for forming a remaining portion of the transverse profile of the top surface of one block or a remaining portion of the transverse profile of the bottom surface of an adjacent block, or both; 
 
 wherein at least one end wall of the mold box provides openings for receiving the bottom insert members, the bottom insert members can be received in and retracted from the openings in the at least one end wall of the mold box both horizontally and vertically, and some of the bottom insert members comprise an undercut surface, the undercut surface being provided with a filler block to close a gap between the end wall and the undercut surface. 
 
     
     
       2. The mold of  claim 1  for manufacturing a plurality of interlocking concrete blocks. 
     
     
       3. The mold of  claim 1  wherein the concrete blocks are provided with tongue and groove interlocking structures. 
     
     
       4. The mold of  claim 1  comprising openings in both end walls of the mold box, wherein the bottom insert members extend through both end walls when the draw plate is in position in the mold. 
     
     
       5. The mold of  claim 1  wherein at least one top insert member is formed integrally with at least one of the side walls. 
     
     
       6. The mold of  claim 3  wherein the top insert members extend substantially between the end walls of the mold box, for manufacturing concrete blocks wherein the tongue and groove interlocking structures extend substantially between the ends of the concrete blocks. 
     
     
       7. A system for manufacturing at least one interlocking concrete block in the mold of  claim 1  wherein an exposed face of the at least one concrete block is generally flush with the top face of the mold, comprising a press head for imparting a profile or texture, or both, to the exposed face.